(R)-4-amino-3-(4-chlorophenyl)butanoic acid which is a representative compound of optically active 4-amino-3-(substituted phenyl)butanoic acid compounds is useful as a reflux esophagitis remedy or antispasmodic.
With regard to a method of producing an optically active 4-amino-3-(substituted phenyl)butanoic acid compound, J. Am. Chem. Soc., 2005, 127, 119-125, JP No. Sho-45-16692B and WO2007/066828 disclose a method of reacting a 4-(substituted phenyl)pyrrolidin-2-one compound with a mineral acid such as hydrochloric acid.
With regard to a method of producing a purified optically active 4-amino-3-(substituted phenyl)butanoic acid compound from the resulting crude optically active 4-amino-3-(substituted phenyl)butanoic acid compound, JP No. Sho-45-16692B discloses a method of making an aqueous solution containing a hydrochloride of a crude optically active 4-amino-3-(substituted phenyl)butanoic acid compound contact an ion-exchange resin and concentrating the resulting solution, and recrystallizing the resulting crystal with water-alcohol.